https://www.heraldnet.com/opinion/olympic-athletes-face-health-risks/
http://theconversation.com/is-rugby-league-too-dangerous-25446
https://www.ncbi.nlm.nih.gov/pubmed/19026015
https://www.theage.com.au/sport/afl/afl-footballers-at-high-risk-of-depression-says-mental-health-group-beyondblue-20170705-gx5eby.html
https://www.outsideonline.com/2198116/are-elite-athletes-healthy
https://www.reuters.com/article/us-soccer-fifa-world/qatar-world-cup-a-potential-health-risk-fifa-idUSTRE6AG2JJ20101117
https://www.bbc.com/sport/39333763